Tag Archive for: BCR

Bayou Land Conservancy Ribbon Cutting on Spring Creek

On Friday, 10/13/2023, Bayou Land Conservancy (BLC) staff and board members met with supporters and legislators for a ribbon-cutting ceremony at BLC’s new Arrowwood Preserve on Spring Creek in Tomball west of 249.

BLC’s Arrowwood Preserve is in the floodplain of Spring Creek just north of Lone Star College – Tomball.

Land Donated by Two Sand Miners in 2020

The occasion: dedication of a new outdoor classroom for environmental education. Years of work that began with the donation of 117 acres to the Bayou Land Conservancy in 2020 culminated yesterday. Two sand miners, Don Poarch and Joe Swinbank, owners of Sprint Sand & Clay, donated the ecologically diverse land across Spring Creek from Lone Star College-Tomball.

The preserve takes its name, Arrowwood, from a 6-8 foot shrub that’s a member of the Honeysuckle family. The preserve marks the western extent of the plant’s natural range.

Since acquisition of the land, BLC staff, volunteers and supporters have developed a management plan, blazed trails, erected boardwalks, and built the new outdoor classroom.

BLC developed the open-air classroom in partnership with William & Madeleine Welder Smith Foundation; The Ralph H. and Ruth J. McCullough Foundation; and Plains All-American Pipeline Company.

An Ecological Gem Now an Outdoor College

The photos below show some of the quiet, natural beauty of the Arrowwood Preserve.

Arrowwood is 117 acres of wetlands also populated by hardwoods and some pines.

Spring Creek cuts through the Arrowwood Preserve.
View looking south from above the new outdoor classroom.
Looking East. The preserve extends to SH249, left to right in the middle.
Jill Boullion, Executive Director of the BLC, cuts the ribbon to honor years of hard work by staff, board members and supporters. New outdoor classroom in background.
After the ribbon cutting, attendees explored the beauty of wilderness in the city.

The land will connect to the Spring Creek Greenway which extends all the way southeast to US59.

Value of Nature in Flood Mitigation

It’s hard to put an exact dollar figure on the value of such a preserve. Traditional benefit/cost ratios used in flood-mitigation projects quantify the benefits of massive engineering/construction projects against the cost of avoided damages.

But this land is still natural. So damage to structures is not a consideration. The value of damages avoided would depend on how many people with bad judgement might choose to build on land that goes deep under water during frequent floods. At 249, Spring Creek floodwaters rose 11.4 feet above flood stage during Harvey. That equals 27.5 feet above the normal elevation!

Need for New Formula to Weigh Prevention Against Correction

But there’s another way to look at this: the value of prevention compared to the cost of correction. Our parents all taught us that an ounce of prevention is worth a pound of cure.

The current mapped floodplains around and in Arrowwood look like this.

From FEMA’s National Flood Hazard Layer Viewer. Striped area = floodway of Spring Creek. Aqua = 1% annual chance of flooding. Tan = .02% annual chance.

Keep in mind that the map above was drawn in 2014 – before Harvey. FEMA has not yet released new post-Harvey flood maps. The floodplains will reportedly expand by 50% to 100%.

So, protecting this land from development will save money several ways. It will eliminate or reduce the:

  • Injuries and lives lost.
  • Cost of flood repairs.
  • Disruption to people’s lives after a flood.
  • Wasted construction dollars in unsafe areas that could have built safe homes on higher ground.
  • Buyouts after repetitive flooding.
  • Loss of home values.
  • Lawsuits.
  • Urban decay.
  • Taxpayer subsidies for the National Flood Insurance Program.
  • Cost of engineering and environmental studies designed to determine how to fix the problems.
  • Construction costs to build flood-mitigation measures, such as stormwater detention basins and channel widening
  • The need for expensive bulkheads and dikes to control river migration.
  • Higher tax rates to pay for many of the costs above.

Then, balance all those uncertainties and negatives against the positives of preservation.

Forests also slow down floodwaters by creating friction. This reduces severity of damage and gives people downstream more time to evacuate if necessary.

Clearly, determining the value of preservation demands a different kind of formula that considers different costs and different benefits.

Perhaps the next generation of future homeowners and leaders from Lone Star College will learn such things at BLC’s new outdoor classroom on Spring Creek and change the world for the better. I hope so.

Support Bayou Land Conservancy

This is an area that should stay natural forever. And with the help of the Bayou Land Conservancy, it will. BLC is an organization making a huge difference in a quiet way. It deserves the support of each and every one of us.

Posted by Bob Rehak on 10/14/23

2237 Days since Hurricane Harvey

Lake Houston Gates Project Moves Closer to Reality

The Lake Houston Gates Project is moving closer to reality with breakthroughs on the benefit/cost ratio, funding and endorsements.

City of Houston Mayor Pro Tem Dave Martin and Chief Recovery Officer Stephen Costello provided updates on 2/27/23 at City Hall on the Lake Houston Gates Project. The wide-ranging, hour-long discussion covered several related topics. They included:

  • A critical path for construction
  • Dredging of the lake
  • Funding for gates and dredging
  • Several related engineering studies
  • A favorable ruling from FEMA on the Benefit-Cost Ratio
  • An endorsement to the area’s legislators by the Greater Houston Partnership.

Need For Gates

For those new to the area, the City of Houston has been pushing to add gates to the Lake Houston Dam ever since Harvey in 2017. Upstream, Lake Conroe’s gates can release 150,000 cubic feet per second (CFS). But Lake Houston’s can only release 10,000 CFS.

The disparity in discharge capacity complicates joint-reservoir-management and pre-release strategies designed to avoid flooding by reducing the water level in Lake Houston.

Lake Houston releases cannot keep up with Lake Conroe’s. And pre-releasing water from Lake Houston takes so long that storms can veer away during the lowering process, often resulting in wasted water. That’s an important consideration for a water-supply lake.

According to Martin and Costello, the gate project will:

• Serve as the first phase of a long-term effort to extend the life of the Dam
• Enable the rapid lowering of lake levels in advance of a flood
• Eliminate the need for a seasonal lowering of both Lake Houston and Lake Conroe
• Provide potential water-rights savings
• Protect an estimated 5,000 residential properties in the surrounding area
• Yield an estimated half billion dollars in economic benefits during the life of the project

Gates, Funding, BCR, Studies

Preliminary engineering studies evaluated about a dozen different alternatives for adding discharge capacity to Lake Houston. The City initially favored adding crest gates to the spillway portion of the dam.

However, the City discarded that idea as “too risky” after further study. The engineering company cautioned the City that it would have a difficult time finding contractors willing to risk modifying a 70-year old concrete dam. The potential liability was just too great. So the City then revisited adding various numbers of tainter gates to the eastern, earthen portion of the dam.

Because tainter gates exceeded FEMA’s funding, the City had initially focused on crest gates. But after investigating the safety issues, the City decided to seek more funding for tainter gates instead.

The City now recommends adding 11 tainter gates.

Recommended location for new tainter gates is next to old ones, not farther east as I conjectured earlier.

The picture below is slightly wider and shows more of how both halves of the dam come together.

If funding comes through, new gates would go in the upper right along the earthen portion of the dam, next to the old gates.
Funding Needs

FEMA initially set aside $50 million for the gates. Plus Harris County committed $20 million in the 2018 Flood Bond to attract FEMA’s match. But the latest construction estimates show eleven tainter gates could cost between $200 and $250 million.

After engineering and environmental studies, only $68.3 million in funding remains. That includes an earmark secured by Congressman Dan Crenshaw. So the City is seeking another $150 million from the State of Texas. Martin and Costello have made weekly trips to Austin so far during this session to line up support from legislators, committee chairs, and the Texas Division of Emergency Management.

Social Benefits Improve Benefit/Cost Ratio

All this is suddenly possible because of a favorable ruling from FEMA on the benefit-cost ratio (BCR).

For years, Houston had struggled to get the BCR for the gate project above 1.0 (the point at which benefits exceed costs). Usually, FEMA strictly interprets benefits as “avoided damages to structures.”

But Houston Mayor Sylvester Turner and Costello met with FEMA to argue that the problem was much bigger than damaged structures.

As a result, FEMA allowed the City to add the value of “social benefits” to the BCR. Social benefits can include such things as avoiding lost wages when businesses are destroyed; transportation disruptions that reduce the region’s productivity; reducing negative impacts on student achievement when schools are disrupted; and more.

The social-benefit ruling covers a number of City projects, not just the gates. It should also benefit other areas, especially rural ones.

Said Costello, “The minute the social benefits came in, everything was great.” Instead of struggling to reach 1.0, the City is now far above it.

Greater Houston Partnership Endorsement

With that out of the way, the Greater Houston Partnership wrote a powerful letter to state legislators seeking their support for the gate project. See below.

Greater Houston Partnership letter endorsing Lake Houston Gates. For a printable PDF, click here.

The Partnership includes business leaders from 900 member companies in the 12-county Houston Region.

Dredging Update

While pressing ahead with the gates project, the City is also working on a long-term dredging plan for the lake and working with the SJRA on sedimentation and sand-trap pilot projects.

The Texas Water Department Board (TWDB) has estimated sediment inflow to Lake Houston at about 380 acre-feet of material annually.

The lake has already lost more than 20,000 acre feet of capacity due to sedimentation. That worsens flooding. While the Federal Government supports efforts to improve Lake Houston now, the chances of getting more money in the future will be reduced – unless we can show that we’re at least keeping pace with annual sediment deposits.

Since Harvey, FEMA, the Army Corps, TWDB, and City of Houston have removed almost 4 million cubic yards of material from the lake at a cost of $226 million.

We have to prevent more sediment from coming downstream or dredge it after it gets here.

Stephen Costello, City of Houston Chief Recovery Officer

The City is currently lobbying for another $50 million for maintenance dredging to add to the money secured in the last legislative session by now-retired State Representative Dan Huberty. New Representative Charles Cunningham will reportedly now carry that banner forward along with State Senator Brandon Creighton.

Legislative News to Follow

March 10th is the last day to file bills in the Texas Legislature this year. Please visit the legislation page on ReduceFlooding.com for updates once bills are filed and start moving forward in Austin.

Thanks to all of our elected and appointed representatives who have pushed so hard on so many fronts for the last 2008 days to tie all the pieces of this complicated flood-mitigation puzzle together.

Posted by Bob Rehak on 2/27/2023

2008 Days since Hurricane Harvey